In the chapter dealing with Oils and Fats, their Saponification Equivalents are given in preference to Saponification Values, as it has been our practice for some years to express our results in this way, as suggested by Allen in _Commercial Organic Analysis_, and all our records, from which most of the figures for the chief oils and fats are taken, are so stated. For the illustrations, the authors are indebted to Messrs. E. Forshaw & Son, Ltd., H. D. Morgan, and W. J. Fraser & Co., Ltd. W. H. S. H. A. A. LONDON, _September_, 1908. CONTENTS PAGE CHAPTER I. INTRODUCTION. 1 Definition of Soap--Properties--Hydrolysis--Detergent Action. CHAPTER II. CONSTITUTION OF OILS AND FATS, AND THEIR SAPONIFICATION 6 Researches of Chevreul and Berthelot--Mixed Glycerides--Modern Theories of Saponification--Hydrolysis accelerated by (1) HEAT OR ELECTRICITY, (2) FERMENTS, Castor-seed Ferment, Steapsin, Emulsin, and (3) CHEMICAL REAGENTS, Sulphuric Acid, Twitchell's Reagent, Hydrochloric Acid, Lime, Magnesia, Zinc Oxide, Soda and Potash. CHAPTER III. RAW MATERIALS USED IN SOAP-MAKING 24 Fats and Oils--Waste Fats--Fatty Acids--Less-known Oils and Fats of Limited Use--Various New Fats and Oils Suggested for Soap-making--Rosin--Alkali (Caustic and Carbonated)--Water--Salt--Soap-stock. CHAPTER IV. BLEACHING AND TREATMENT OF RAW MATERIALS INTENDED FOR SOAP-MAKING 41 Palm Oil--Cotton-seed Oil--Cotton-seed "Foots"--Vegetable Oils--Animal Fats--Bone Fat--Rosin. CHAPTER V. SOAP-MAKING 45 Classification of Soaps--Direct combination of Fatty Acids with Alkali--Cold Process Soaps--Saponification under Increased or Diminished Pressure--Soft Soap--Marine Soap--Hydrated Soaps, Smooth and Marbled--Pasting or Saponification--Graining Out--Boiling on Strength--Fitting--Curd Soaps--Curd Mottled--Blue and Grey Mottled Soaps--Milling Base--Yellow Household Soaps--Resting of Pans and Settling of Soap--Utilisation of Nigres--Transparent soaps--Saponifying Mineral Oil--Electrical Production of Soap. CHAPTER VI. TREATMENT OF SETTLED SOAP 60 Cleansing--Crutching--Liquoring of Soaps--Filling--Neutralising, Colouring and Perfuming--Disinfectant Soaps--Framing--Slabbing--Barring--Open and Close Piling--Drying--Stamping--Cooling. CHAPTER VII. TOILET, TEXTILE AND MISCELLANEOUS SOAPS 77